Research And Development Of Power Factor Correction Module For EV Charging System

With the rapid development of electric vehicle industry,on-board charging technology has become a research hotspot in recent years.Generally,the on-board charger adopts two-stage structure,which is composed of front stage PFC and rear stage DC/DC converter.In this paper,the PFC part is taken as the research object,and a totem-pole PFC with SiC MOSFET is designed which works in current continuous mode(CCM)and has a maximum output power of 2.5Kw.Firstly,this paper introduces and compares various mainstream PFC topologies.Among them,Totem-pole PFC was selected as the research object due to its advantages of low common-mode noise,few power components and high efficiency.However,the working mode analysis of totem pole topological PFC shows that the circuit cannot work in continuous current mode due to the serious reverse recovery problem of MOSFET body diode as a continuation diode.To solve this problem,this paper introduces two improvement schemes.The first one is to adopt the interleaved totem-pole bridgeless topology.The proposed topology is composed of two interleaved and intercoupled cells.The two cells operate in phase-shift mode,and for individual cells,they operate alternatively in discontinuous current mode(DCM).The second one is based on the traditional totem-pole topology,a SiC MOSFET with low reverse recovery is selected to replace the Si MOSFET in application,so as to improve the efficiency and stability of the system.Considering the first scheme is complex,the design is based on the second scheme.After that,according to the design objectives,the paper calculated and selected the main inductor,DC capacitor and power switches,and design the main circuit and drive circuit by Altium Designer software.Next,the classical control strategies of totem pole PFC are introduced and analyzed.And the control circuit based on ICE2PCS01 G chip is simulated by MATLAB/SIMULINK platform.After the function verification of the control circuit through the simulation,the hardware design of control circuit is carried out.Finally,a totem-pole PFC experimental platform was built for experiment function verification.The experimental results show that the inductance current is sinusoidal and can follow the change of input voltage well.However,when designing the control loop,the influence of EMI filter on the circuit and the interference on sampling circuits are not considered,and the inductive current lags behind the input voltage.This is the focus in further research.